Global warming and polar tidewater glacier response: A Canadian IPY project on Belcher Glacier, Nunavut

B.Beauchamp

Sarah Boon(1); Dave Burgess(2); Luke Copland(3); Gwenn Flowers(4); Jeff Kavanaugh(2);

Shawn Marshall(5); Martin Sharp(2); Lev Tarasov(6)

(1)U of N.B.C, (2)U. of Alberta, (3)U. of Ottawa, (4)Simon Fraser, (5)U. of Calgary,

(6)M.U.N.

Rahmstorf et al, Science Express, Feb 2007

Mauna Loa CO2 record

Global Mean Annual Air Temperaturec.f. IPCC Scenarios

Global Mean Sea Levelc.f. IPCC Scenarios

THE CLIMATE SYSTEMTHE CLIMATE SYSTEM IS MORE SENSITIVE IS MORE SENSITIVE THAN WE THOUGHTTHAN WE THOUGHT

WHAT’S DRIVING THE SEA LEVEL RISE ?WHAT’S DRIVING THE SEA LEVEL RISE ??

ENHANCED MASS LOSS FROM GREENLAND

Luthcke et al, Science, 2006Alley et al., Annals of Glaciology, in press

WHY THE ENHANCED LOSS?WHY THE ENHANCED LOSS?

ACCELERATED OUTLET GLACIEROUTLET GLACIER FLOW

Rignot &Kanagaratnam,Science, 2006

Ekstrom et al,Science, 2006

OutletGlacier

velocitiesm/yr

GlacierEarthquakes

OUTLET GLACIEROUTLET GLACIER RETREAT, RETREAT, THINNING AND ICEBERG CALVINGTHINNING AND ICEBERG CALVING

I. Howat et al., GRL, 2005

Helheim Glacier

Frontal Retreat

2000

2004

Velocity

Thickness Change

WHAT’S DRIVING THESE WHAT’S DRIVING THESE CHANGES?CHANGES?

• Two main hypotheses:– From the top – increased

or more widespread penetration of surface meltwater to the glacier bed enhances sliding

– From the bottom – terminus destabilisation by flotation (due to rising sea level or thinning caused by increased surface or marine melt) reduces flow resistance

• But which is it ? Hard to measure in Greenland

A. Gardner

IPY GLACIODYN: International

• Researchers from 17 countries• Tidewater Arctic glaciers – role of dynamics in

response to climate warming– Canada, Alaska, Greenland, Iceland, Svalbard, Russia

B.Danielson

IPY GLACIODYN Canada

Canadian ParticipantsMartin Sharp, Jeff Kavanaugh, (U. Alberta) Shawn Marshall (U. Calgary), Gwenn Flowers (SFU)Sarah Boon (UNBC), Luke Copland (U. Ottawa)Trevor Bell, Lev Tarasov (Memorial)Dave Burgess, Laurence Gray (CCRS)

International CollaboratorsTony Payne, Jemma Wadham (Bristol University, UK)Bernd Kulessa (University of Wales, Swansea)Andy Smith (British Antarctic Survey)

Devon

Queen ElizabethIslands

Canadian site: Devon Island Ice Cap

Study site: Belcher Glacier

Goals

1. Develop high order coupled model of outlet glacier dynamics– incorporate surface mass balance, glacier hydrology, ice

flow and iceberg calving

2. Collect detailed field and remotely sensed data– Design, initialize, drive, and validate model

3. Run model– Explore Belcher Glacier response to climate change

• atmospheric and oceanic climate • amount and distribution of surface water inputs to glacier bed• Ice dynamics, terminus stability and iceberg calving• What are the important processes?

snow

• Surface mass balance model

• Whole ice cap flow model

• Coupled hydrology/ thermomechanical outlet glacier flow model

• Iceberg calving mechanics

Methods: Modelling

Lev Tarasov

G. Flowers

• Mass balance – radar, ice cores, AWS,

stakes, remote sensing of summer melt

• Hydrology & Drainage– remote sensing, time

lapse photography, hydrometric measurements,

• Topography– Kinematic GPS,

Airborne laser altimetry, Photogrammetry

Methods: Surface Processes & Properties

S. BoonThickness Changes 1960-2005

Distance from Glacier Head (km)

Surface elevation change

(m/yr)

B.Danielson

• Subglacial topography– RES, GPR

• Bed properties and their temporal variability– seismic reflection

and monitoring

Methods: Sub-surface characteristics

NOAA

M. Davis

W.Krabill

Methods: Offshore bathymetry and water column properties

• RCGS Amundsen

• Remote sensing– InSAR

• Field measurements– wireless GPS

Methods: Ice velocities

D. Burgess

D. Burgess et al., J.Glaciology, 2005

• On what timescale does Belcher Glacier respond to climate warming?

• How is glacier response regulated by changes in the rate and mechanism of ice flow? If so, what causes these changes?

• How do these changes amplify those caused by surface mass balance alone?

Key questions (1)

F. Cawkwell

• Are changes in flow dynamics and iceberg calving related, and how?

• What controls the calving rate and its variation over time – is ocean climate important?

Key questions (2)

Vexcel A.Gardner

Challenges

• NSERC IPY/PCSP Logistics mis-communication: dollar stretching

• Polar Bears

Funding

• NSERC – IPY SRO– RTI– Discovery Grant– Northern Research Supplement

• CFI • ASRIP, OIT• ArcticNet• PCSP

F. Cawkwell